破碎围岩大断面回采巷道加强支护形式与参数研究

Research on Strengthening Support Form and Parameter in Large Section Mining Tunnel with Broken Surrounding Rocks

煤矿地下开采过程中时常需要开挖一些大跨度的巷道或峒室。在围岩风化程度小,岩体比较完整的情况下,采用锚杆加固等一般的支护方式即可以满足安全生产的要求。但当大跨度巷道围岩比较破碎,尤其当顶板风化严重时必须采取有效的加强支护措施来保证巷道的稳定性。结合冀中能源股份有限公司葛泉矿东井11912工作面大断面切眼的煤层赋存条件和开采技术条件,利用散体地压的塌落拱理论和结构力学原理,对由Q235 40c型热轧工字钢组成的一梁两柱式加强支护结构的安全性进行计算分析。结果表明,选定的加强支护结构形式及与之匹配的支护参数,能够满足巷道的使用与安全要求,可为类似条件巷道的支护设计提供参考依据。

Large span tunnels excavation and chambers drilling are common in underground coal mining. Tunnel safety can be ensured by using normal supporting forms such as anchor reinforcement when the weathering degree of surrounding rock is relatively low and the rock is fairly intact. However, when the surrounding rocks of large span tunnel are crushing, especially when the weathering degree of roof rock is serious. Thus, effective supporting measure should be taken in order to ensure the stability of the tunnel. By means of occurrence conditions of coal seams and mining technical conditions of the large-span cutting hole in Gequan coal mine 11912 working face of Jizhong Energy Resource Company, applying the pressure arch theory and structural mechanics theory, this paper analyzes the safety of the strengthened support made of Q234 20a type joist steel with one beam and two columns. The results show that the selected strengthened support and the supporting parameter which matches it can meet the requirements of safety design and application. It can also provide references for other similar supporting designs of tunnel.